Remove the gas cap, then look for a Schrader valve on the fuel rail. If it has one release the pressure there. If it has none, then wrap a rag around the fuel filter coupling and prepare for a spray of fuel when you disconnect the fuel line from the fuel filter.
Remove the fuel fill cap that should take fuel pressure off and it would be safe to release the filter and change it!
5 quarts WITH FILTER CHANGE
( 5 quarts ) with engine oil filter change
take the gas cap off
( 5 quarts ) with engine oil filter change
remove fuel pump fuse. then start engine it will stall when fuel runs out change filter then replace fuse.
( 5 quarts ) with engine oil filter change
( 5 quarts ) with engine oil filter change for the 4.0 liter SOHC , V6 engine in a 2006 Mercury Mountaineer
If you can blow through the filter with no constrictions it's fine.
On a 1997 Mercury Mountaineer : I assume the fuel filter would be in the same location as a 1997 Ford Explorer : ( underneath the Mountaineer , below the drivers door , mounted on the frame rail )
On a 2001 Mercury Mountaineer : Underneath the Mountaineer , below the drivers door , mounted on the frame rail
You have to release the fuel pressure at the schrader valve on the fuel rail. The filter is located under the car on the driver's side on the frame just after the tank. It will require a special tool to release the disconnect.